Wireless Connector System

ABSTRACT

Various embodiments of a wireless connector system are described. The system has a transmitter module and a receiver module that are configured to wirelessly transmit electrical energy and/or data via near field magnetic coupling. The wireless connector system is designed to increase the amount of wirelessly transmitted electrical power over a greater separation distance. The system is configured with various sensing circuits that alert the system to the presence of the receiver module to begin transfer of electrical power as well as undesirable objects and increased temperature that could interfere with the operation of the system. The wireless connector system is a relatively small footprint that is designed to be surface mounted.

RELATED APPLICATION

This application is a continuation of, and claims priority to, U.S. Non-Provisional application Ser. No. 15/686,920, filed on Aug. 25, 2017, and entitled “Wireless Connector System,” which in turn claims priority to U.S. Provisional Application No. 62/379,940, filed on Aug. 26, 2016, the disclosure of which is entirely incorporated herein by reference.

TECHNICAL FIELD

The present disclosure generally relates to the wireless transmission of electrical energy and data. More specifically, this application relates to an electrical device that facilitates the wireless transmission electrical energy at multiple operating frequencies and frequency bands.

BACKGROUND

Prior art electrical connectors are traditionally constructed with a plurality of pins that physically plug into a corresponding receiving port. Each half of these connectors are typically assigned a male and a female designation which are subsequently mated to form an electrical contact.

Fundamentally, an electrical connector is an electro-mechanical device comprising electrical conductors that are used to electrically and mechanically join other conductors, electrical terminals of apparatus and equipment to create an electrical circuit. The term electrical connector generally covers a wide range of devices designed to connect, for example, small conductors employed in communication circuits to large cables and bus-bars. They are typically passive and consist of plugs (male) and jacks (female). The connection may be temporary, as for portable equipment, or may serve as a permanent electrical joint between two wires or devices.

Examples of prior art connectors include USB and HDMI plugs. The power levels for these connectors range from a few Watts to about 100 Watts (as, for example, for the recently released USB-C). These connectors are also constructed and rated to provide data capabilities of up to 10 Gbps or higher. In addition, there are numerous types of connectors, ranging from a simplistic “Wire Nut” to more complex USB connectors or RF connectors, which mostly comply with known connection interface standards, for example, Ethernet, CAN, IO-Link, and RS485. The power levels for these connectors can range from microwatts to megawatts.

Typical connector types are in-line splice couplers, T-tap connectors, terminal lugs, and stud connectors. Couplers join conductors end to end. T-tap connectors join a through conductor to another conductor at right angles. Terminal lugs join the conductor to a drilled tongue for bolting to the terminals of equipment. Stud connectors join the conductor to equipment studs. The stud clamp is typically threaded or smooth to match the stud.

Other connector types include split-bolt connectors that are generally of a compact construction and are widely used for splicing and taping wires. The split-bolt connector comprises a bolt-shape casting having a wide and deep lengthwise slot. Conductors are inserted in the slot and a nut clamps the conductors together inside the bolt.

Yet another type of connector is an expansion or flexible connector that allows for limited motion between the connected conductors. The clamp portions of the connector are joined by short lengths of flexible copper braid and may also be held in alignment by a telescoping guide.

Another type of traditional connectors include separable type connectors that generally consist of matched plugs and receptacles. Separable type connectors are designed to separate or disconnect a conductor or group of conductors from a circuit or system. Separable type connectors are commonly used for the connection of portable devices and appliances to an electric wiring system.

Traditional connectors also include locking type connectors that are designed such that a plug is inserted and twisted through a shaped opening, locking it securely in place. Thus, when connected, locking type connectors are generally not separated by a mechanical strain such as a pull on the connected cord.

Electrical connectors are generally characterized by a variety of parameters which include, but are not limited to, the number of electrical connections (i.e. pins), physical construction, size, shape, contact resistance, insulation between electrical connections, ruggedness to vibration, resistance to contaminants and pressure, reliability, estimated lifetime (number of connect/disconnect operations before failure), and ease of connecting and disconnecting. The physical electrical connections, such as pins, of traditional connectors, provide a passage for electrical energy and data. In addition, characteristics of electrical power and data, such as power ratings and data rates are also utilized to characterize various electrical connectors.

Operation of these prior art connectors is typically dependent on the physical connection between two electrically conductive components, such as a pin and a respective pad, port or jack within which the pin is received. The physical connection occurs at a microscopic level over a relatively small interface area between the physically contacting electrically conductive components, such as a pin and a corresponding receptacle. Furthermore, traditional connectors generally require a significant amount of mechanical force to ensure an adequate physical connection of the connecting members so that an electrical signal is safely passed therethrough. This microscopic connecting area may become affected by different factors, such as harsh environments, vibration as well as wear and tear over time under normal operating conditions.

As such, the performance and reliability of these prior art connectors are largely dictated by the integrity of their physical connection. Furthermore, these traditional mechanical connectors generally require physical contact at a precise alignment to function properly.

Furthermore, wired connectors typically do not allow any relative motion between the male and the female portions. Over time, due to this physical contact, these mechanical connection points typically experience forces that can fatigue and damage the pin or port, thereby preventing proper functionality. Such prior art connectors may wear, flex, or may become corroded or damaged. As a result, the physical connection between the corresponding male and female portions such as a pin and respective port may become compromised, thereby resulting in a loss of data or electrical energy transfer therebetween due to an impaired or inoperable connector. Contamination, moisture and liquid ingress in a consumer, medical, military or industrial environment may pose undesirable problems, including outright failure to perform which may result in hazardous, unsafe or threatening conditions. In addition to improper functionality due to faulty physical connections, methods of wired communication, such as Universal Asynchronous Receiver and Transmitter Protocol (UART), Inter-Integrated Protocol (I2C), and Serial Peripheral Interface Protocol (SPI), may have limited bandwidth capabilities in comparison to various wireless methods of communication.

Moreover, developments in automation and robotics have increased the demand for transferring electrical power between dynamically moving parts and assemblies of many different industrial devices. There is a significant challenge to transfer power under these conditions using conventional wired electrical connectors.

In addition to the deficiencies given above, such prior art connectors typically comprise an electrical cord that extends from the connector. Such electrical cords are generally not desired as they may also become damaged, resulting in a loss of data or energy transfer. Furthermore, such electrical cords may excessively occupy critical space and become an impediment to the user. Moreover, exposed or damaged cords may contaminate a sterilized environment. Furthermore, such exposed or damaged cords, for example, cords that have lost their electrical insulation, may become a hazard and potentially cause electrical shock to both humans and animals.

SUMMARY

Therefore, to address these problems, a wireless connector system is provided. In an embodiment, the wireless connector system of the present application enables the wireless transmission of electrical power and/or data between spaced apart transmitter and receiver modules using near field magnetic coupling (NFMC). In an embodiment, the respective transmitter and receiver wireless modules may be insulated and/or hermetically sealed.

The connectors have exposed contact pins and features allowing them to be assembled onto larger electrical circuits, such as a printed circuit board (PCB) or flexible circuit board (FPC) using an electrical component surface mount (SMT) assembly process.

Thus, provided is an electrical connector having a form factor that can replace or eliminate the need for wired connectors.

The wireless connector system of the present application provides a wireless power link that eliminates the need for a physical connection such as an electrical connector that physically joins two components together. Thus, by eliminating the physical connection, the wireless connector or power link can be completely encapsulated, preventing liquids and other debris from inhibiting proper functionality. Without physical contact, mechanical and environmental stresses and wear of the connector are eliminated and a more reliable and robust link to transfer power and data is achieved. This solution also allows for greater misalignment and/or relative movement between the transmitter and receiver compared to prior art connectors. This could allow these connectors to be used in applications which were not previously considered for wired connectors due to their limitations.

In one or more of the embodiments of the present application, a wireless connector system is provided that includes a transmitter module with a first substrate supporting a transmitter antenna, wherein the transmitter antenna is configured to transmit a wireless signal. In addition, the wireless connector system includes a second substrate supporting a transmitter module electronic circuit, wherein the transmitter module electronic circuit is electrically connected to the transmitter antenna. In addition, a first insulator is positioned between the transmitter module electronic circuit and the transmitter antenna. The wireless connector system further includes a receiver module with a third substrate supporting a receiving antenna, wherein the receiving antenna is configured to receive the wireless signal. Furthermore, the wireless connector system includes a fourth substrate supporting a receiver module electronic circuit, wherein the receiver module electronic circuit is electrically connected to the receiver antenna. In addition, a second insulator is positioned between the receiver module electronic circuit and the receiver antenna.

The transmitter and receiver modules of the wireless connector system of the present application are designed with electrical circuitry that increases the amount of wirelessly transmitted electrical power over a greater separation distance between the transmitter and receiver modules. In addition, the wireless connector system may be configured with various sensors that detect the presence of an electrical energy transfer module, heat, or an undesirable foreign object. In an embodiment, the operation of the transmitter and/or the receiver module may be dependent upon information obtained from various sensors that may or may not be incorporated within the module.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of an embodiment of the wireless connector system of the present application.

FIG. 2 shows a block diagram of an embodiment of the wireless connector system of the present application.

FIGS. 3-6 illustrate electrical block diagrams of embodiments of the transmitter module.

FIGS. 7, 8A, and 8B show embodiments of a switching capacitance circuit that may be incorporated within the impedance matching circuit of the transmitter or receiver circuit of the present application.

FIGS. 9-12 illustrate electrical schematic diagrams of embodiments of the transmitter circuit.

FIG. 13 illustrates a block diagram of an embodiment of the receiver module of the wireless connector system of the present application.

FIG. 14 illustrates an electrical schematic diagram of an embodiment of the receiver circuit within the receiver module.

FIG. 15 is an electrical block diagram of an embodiment of the receiver module.

FIG. 16 illustrates an electrical schematic diagram of an embodiment of the receiver circuit within the receiver module.

FIG. 17 is an electrical block diagram of an embodiment of the receiver module.

FIGS. 18A-18D illustrate embodiments of capacitors within the impedance matching circuit that may be utilized in the transmitter or receiver circuit.

FIGS. 19-21 show embodiments of the transmitter and receiver modules of the present application.

FIGS. 22-23 illustrate embodiments of the transmitter and receiver modules of the wireless connector of the present application electrically connected to a host device.

FIG. 24 shows an embodiment of the positioning of the antenna and transmitter and receiver circuit board relative to shielding and spacer materials within the transmitter and receiver module housings.

FIGS. 25 and 26 illustrate embodiments of electrically connecting the transmitter and receiver modules to a circuit board of a host device.

FIGS. 27-30 illustrate embodiments of alternative structures of the transmitter or receiver modules of the present invention.

FIG. 30A is a cross-sectional view of the embodiment of the assembled transmitter module or receiver module shown in FIG. 30.

FIGS. 31-34 illustrate different embodiments of the transmitter or receiver module shown in FIGS. 27-30 mounted to a circuit board.

FIG. 35 shows an embodiment of an antenna that may be utilized in either or both the transmitter and receiver modules.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.

The wireless connector system 10 of the present disclosure provides for the wireless transfer of electrical energy and/or data. More specifically, the wireless connector system 10 of the present invention provides for the wireless transfer of electrical energy and/or data via near field magnetic coupling. In an embodiment, the wireless connector system 10 comprises a transmitter module 12 configured to transmit electrical energy and a receiver module 14 configured to receive electrical energy transmitted by the transmitter module 12. In an embodiment, the transmitter module 12 is positioned spaced from the receiver module 14 so that electrical energy is wirelessly transmitted from the transmitter module 12 across a separation distance or gap 16 (FIGS. 2 and 19-22) where it is received by the receiver module 14. Thus, the combination of the transmitter and receiver modules 12, 14 provides for the wireless connector system 10 so that electrical energy can be transferred wirelessly without the need of a physical connection therebetween.

In this application, the inventive concepts particularly pertain to near-field magnetic coupling (NFMC). Near-field magnetic coupling enables the transfer of electrical energy and/or data wirelessly through magnetic induction between a transmitting antenna and a corresponding receiving antenna. The NFC standard, based on near-field communication interface and protocol modes, is defined by ISO/IEC standard 18092. Furthermore, as defined herein “inductive charging” is a wireless charging technique that utilizes an alternating electromagnetic field to transfer electrical energy between two antennas. “Resonant inductive coupling” is defined herein as the near field wireless transmission of electrical energy between two magnetically coupled coils that are tuned to resonate at a similar frequency. As defined herein the term “shunt” means an electrically conductive pathway that is created by electrically joining two points of a circuit such that an electrical current or an electrical voltage may pass therethrough. As defined herein “mutual inductance” is the production of an electromotive force in a circuit by a change in current in a second circuit magnetically coupled to the first. As defined herein a “shielding material” is a material that captures a magnetic field. Examples of shielding material include, but are not limited to ferrite materials such as zinc comprising ferrite materials such as manganese-zinc, nickel-zinc, copper-zinc, magnesium-zinc, and combinations thereof. A shielding material thus may be used to direct a magnetic field to or away from an object, such as a parasitic metal, depending on the position of the shielding material within or nearby an electrical circuit. Furthermore, a shielding material can be used to modify the shape and directionality of a magnetic field. As defined herein a parasitic material, such as a parasitic metal, is a material that induces eddy current losses in the inductor antenna. This is typically characterized by a decrease in inductance and an increase in resistance of the antenna, i.e., a decrease in the quality factor.

FIG. 1 shows a generic block diagram of the wireless connector system 10 of the present invention. As shown, the system 10 comprises the transmitter module 12 spaced from the receiver module 14 by the gap 16. The transmitter module 12 comprises a transmitter module circuit 18 that is electrically connected to a transmitter antenna 20. In an embodiment, the transmitter antenna 20 may comprise one or more antennas to facilitate the wireless transfer of electrical power and/or data. In an embodiment, the transmitter module circuit 18 is configured to modify electrical energy that is received from an electrical source (not shown) or a transmitter host device 22 that is electrically connected to the transmitter module 12. In an embodiment, the transmitter host device 22 may comprise an electrically operated device, a circuit board, an electronic assembly, or other electronic device. Examples of transmitter host devices include, but are not limited to, a medical device, a device that comprises an integrated circuit, such as a computer, and personal electronic devices, such as, but not limited to, eye glasses and clothing configured with electronic components.

The transmitter antenna 20 is configured to wirelessly transmit the electrical energy conditioned and modified for wireless transmission by the transmitter module circuit 18 via near-field magnetic induction coupling. In an embodiment, the transmitter module 12 may be electrically powered by the transmitter host device 22.

In an embodiment, the receiver module 14 comprises a receiver module circuit 24 that is electrically connected to a receiver module antenna 26. The receiver antenna 26 is configured to receive electrical energy and/or data that is transmitted by the transmitter module 12. In an embodiment, the receiver module circuit 24 is configured to condition the received wireless electrical energy such that it can be used to electrically power a device or provide electrical energy to an electrical energy storage device such as a battery or capacitor.

In an embodiment, the receiver module 14 is electrically connected to a receiver host device 28. In an embodiment, the receiver host device 28 comprises an electrically operated device, a circuit board, an electronic assembly, or other electronic device. Examples of receiver host devices include, but are not limited to, a medical device, a device that comprises an integrated circuit, such as a computer, and personal electronic devices, such as not but limited to eye glasses and clothing configured with electronic components. In an embodiment, the receiver module 14 may be electrically powered from an electrical power source 105 (FIG. 17) supplied by the receiver host device 28. It is noted that at least one of the transmitter and receiver modules 12, 14 may be configured as a transceiver thereby enabling either or both the transmitter and receiver modules 12, 14 to transmit and receive electrical power and/or data.

In an embodiment, the transmitter module 12 and the receiver module 14 may be connected to the same host device to facilitate wireless transfer of electrical energy within the host device. Alternatively, the transmitter and receiver modules 12, 14 may be electrically connected to different host devices thereby facilitating wireless transfer of electrical energy between two different devices.

FIG. 2 illustrates a block diagram of an embodiment of the wireless connector system 10 of the present application. As shown, the transmitter module circuit 18 comprises a gate driver 30 and an electrical power amplifier 32. A voltage supply and electrical ground, from the transmitter host device 22 are electrically connected to the gate driver 30 and the electrical power amplifier 32 of the transmitter module circuit 18. In an embodiment, the gate driver 30 is used to control the operation of the electrical power amplifier 32. In addition, a control signal and pulse width modulation signal, from the transmitter host device 22 are electrically connected to the gate driver 30 of the transmitter module circuit 18. In an embodiment, the control signal and pulse width modulator signal are used to control the operation of the transmitter module 12. The receiver module 14, which is illustrated comprising the receiver antenna 26, a rectifier 34 and a voltage regulator 36, is positioned spaced at the gap 16 from the transmitter module 12. As illustrated, an electrical power line, which is electrically connected to the receiver host device 28 and the receiver module circuit 24, exits the receiver module 14 to provide electrical power to a connected receiver host device 28. In an embodiment, the rectifier 34 is configured to rectify the received wireless electrical power from an alternating current electrical power to a direct current electrical power. The voltage regulator 36 is configured to modify the voltage of the received wireless electrical power before it exits the receiver module 14.

FIGS. 3-6 are block diagrams that illustrate embodiments of the transmitter module circuit 18 of the present invention that comprises various transmitter module sub-circuits. As illustrated in the embodiment shown in FIG. 3, the transmitter module circuit 18 comprises an electrical driver sub-circuit 38, an electrical impedance matching or network sub-circuit 40 and a receiver sensing sub-circuit 42. In addition, the transmitter module circuit 18, may comprise a voltage regulator 36 and a master control unit 44. Alternatively, as shown, the voltage regulator 36 and the master control unit 44 may be comprised within the transmitter host device 22.

In an embodiment, the voltage regulator 36 is configured to adjust the amplitude of the voltage of the electrical energy received from an electrical source, such as the transmitter host device 22, by the transmitter module circuit 18. In the embodiment shown, the voltage regulator 36 is electrically connected to an electrical power source 46 and the driver sub-circuit 38. In an embodiment, the electrical power source 46 may comprise an electrical storage device such as an electrochemical cell (not shown), a battery pack (not shown), or a capacitor (not shown). In addition, the electrical power source 46 may comprise an alternating or direct current electrical power from the transmitter host device 22. In an embodiment, the driver circuit 38 controls the operation of the electrical impedance matching or network sub-circuit 40 and/or the transmitter antenna 20. In an embodiment, the driver sub-circuit 38 may comprise an integrated circuit such as a half-bridge integrated circuit. In an embodiment, the driver sub-circuit 38 may be configured to convert at least a portion of the electrical power from a direct current electrical power to an alternating current electrical power for wireless transmission.

In an embodiment, the receiver sensing sub-circuit 42 is configured to detect the presence of the receiver module 14. In an embodiment, if the presence of the receiver module 14 is detected, wireless transmission of electrical power and/or data by the transmitter module 12 to the receiver module 14 is enabled. Likewise, in an embodiment, if the presence of the receiver module 14 is not detected, wireless transmission of electrical power and/or data is prevented from occurring. In addition, the master control unit 44, which may comprise an integrated circuit, is electrically connected to the driver sub-circuit 38. In an embodiment, the master control unit 44 controls the operation of the transmitter antenna 20 and transmitter module circuit 18. The electrical impedance matching or network circuit 40, which comprises at least one capacitor, is electrically connected to the electrical driver sub-circuit 38 and the transmitter antenna 20. The impedance matching circuit 40 provides a capacitance that is designed to adjust and match the electrical impedance of the receiver antenna 26 to a characteristic impedance of the power generator or the load at a driving frequency of the transmitter antenna 20.

In an embodiment, electrical power from an electrical source 46, such as the transmitter host device 22, is received by the voltage regulator 36 and the master control unit 44. A first portion of the electrical power, from the electrical power source 46, is configured to electrically power the components of the transmitter module 12 such as the master control unit 44. A second portion of the electrical power, from the electrical power source 46, is conditioned and modified for wireless transmission to the receiver module 14. In an embodiment, the voltage regulator 36 modifies the amplitude of the voltage of the second portion of electrical power to match the voltage requirements of the receiver host device 28. The second portion of the electrical power, conditioned by the transmitter module circuit 18 for wireless transmission, is received by the transmitter antenna 20 where it is wirelessly transmitted to the receiver module 14.

In an embodiment, as illustrated in FIG. 4, the transmitter module circuit 18 may also be configured with a power stage inverter 48, such as a dual field effect transistor power stage inverter. In an embodiment, the power stage inverter 48 is an electrical amplifier that is electrically connected to the driver sub-circuit 38 and the network analyzer sub-circuit 40. In an embodiment, the addition of the power inverter 48 within the transmitter module circuit 18 enables wireless transmission of an electrical power having an increased amplitude. For example, the addition of the inverter sub-circuit 48 enables the transmitter module 12 to transmit an electrical power from about 300 mW to about 600 mW. Without the embodiment of the power stage inverter 48, the transmitter module 12 is configured to transmit electrical power between about 100 mW to about 300 mW. Also, the power stage inverter 48 may be configured to modify the electrical power to be transmitted from a direct current electrical power to an alternating current electrical power.

As shown in FIG. 5, the transmitter module circuit 18 may be configured with a variety of sensing circuits. In addition to the receiver sensing sub-circuit 42, the transmitter module circuit 18 may also be configured with a thermal sense sub-circuit 50 and/or an object sensing sub-circuit 52. As illustrated, the thermal and object sensing sub-circuits 50, 52 are electrically connected to the transmitter master control unit 44. The thermal sense sub-circuit 50 is configured to monitor the temperature within the transmitter module 12. In an embodiment, if the master control unit 44 through the thermal sense sub-circuit 50 detects that the temperature within the transmitter module 12 to have increased from about 20° C. to about 50° C., the transmitter master control unit 44 prevents the operation of the transmitter module 12. In an embodiment, the thermal sensing sub-circuit 50 may comprise a thermocouple, a thermistor, such as a negative temperature coefficient (NTC) resistor, a resistance temperature detector (RTD), or combinations thereof. In an embodiment, the object detection sub-circuit 52 is electrically connected to the transmitter master control unit 44. In an embodiment, the object detection sub-circuit 52 is configured to detect the presence of an undesired object. In an embodiment, if the master control unit 44 through the object detection sub-circuit 52, detects the presence of an undesired object, the master control unit 44 prevents the operation of the transmitter module 12. In an embodiment, the object detection sub-circuit 52 utilizes an impedance change detection scheme in which the master control unit 44 analyzes a change in electrical impedance observed by the transmitter antenna 20 against a known, acceptable electrical impedance value or range of electrical impedance values. In addition, the object detection sub-circuit 52 may utilize a quality factor change detection scheme in which the master control unit 44 analyzes a change from a known quality factor value or range of quality factor values of the object being detected, such as the receiver antenna 26. In an embodiment, the object detection sub-circuit 52 may comprise an optical sensor, a Hall Effect sensor, or combination thereof. In an embodiment, these sensors, may be monitored using the master control unit 44, a computer (not shown), a comparator (not shown), or other active or passive monitoring methods known to one skilled in the art. Furthermore, the information obtained from the sensors may be used to control operation of the transmitter module 12, the receiver module 14, or the system 10. In addition, the transmitter module circuit 18 may be configured to transmit and receive data 54. In an embodiment, the transmitter module 12 may be configured to communicate to and from the receiver module 14 through modulation and demodulation of the data 54. In an embodiment, the data 54 may comprise information in for form of an electrical voltage and/or an electrical current.

FIG. 6 illustrates an embodiment of the transmitter module circuit 18 of the present application comprising the master control unit 44, the driver circuit 38 comprising a half-bridge driver, the power stage inverter 48 comprising a dual-field effect power stage inverter and the impedance matching circuit 40. A sensing line (SNS) connects the master control unit (MCU) 44 to at least one of the receiver sensing sub-circuit 42, the thermal sensing sub-circuit 50 and the object detection sub-circuit 52.

In an embodiment, as illustrated in FIGS. 7, 8A, and 8B, the impedance matching sub-circuit 40 may comprise a switch capacitance sub-circuit 56. In an embodiment, the switch capacitance sub-circuit 56 comprises an electrical switch 58 and at least two capacitors C₁ and C₂ that are connected in electrical parallel. As shown in FIG. 7, three capacitors C₁, C₂, and C₃ are connected in electrical parallel and the switch 58 is shown between capacitors C₁ and C₂. In an embodiment, the capacitance of the impedance matching circuit 40 may be adjusted by the master control unit 44 by turning the switch 58 on and off, thereby dynamically connecting or disconnecting capacitors within the impedance matching sub-circuit 40 which adjusts the resulting impedance.

FIG. 8A illustrates an alternate embodiment of the switch capacitance sub-circuit 56 in which the switch 58 is electrically connected between capacitors C₄ and C₅, that are electrically connected in parallel. In addition, inductor Li and resistor R₁ are electrically connected to capacitors C₄ and C₅. FIG. 8B illustrates an alternate embodiment of a switch capacitor sub-circuit 56 comprising first and second switches 58, resistors R₂, R₃, and R₄, capacitors C₆ and C₇, and diodes D₁-D₄ that may be incorporated within the transmitter module circuit 18 or the receiver module circuit 24 to dynamically adjust the impedance of the impedance matching circuit 40.

FIGS. 9-12 are electrical schematic diagrams that illustrate embodiments of the transmitter module circuit 18 of the present application. In an embodiment, the transmitter module circuit 18 comprises the impedance matching sub-circuit 40, an electrical power sub-circuit 60 and a sensing sub-circuit 62, such as the receiver module sensing sub-circuit 42, the thermal sensing sub-circuit 50, the object sensing sub-circuit 52, or combinations thereof. In an embodiment, the electrical power sub-circuit 60 modifies and configures electrical power received from the electrical power source 46 to power the various circuits comprising the transmitter module 12 and provide electrical power for wireless transmission to the receiver module 14.

As illustrated in the embodiments shown in FIGS. 9 and 10, the electrical power sub-circuit 60 comprises the driver sub-circuit 38, such as a half-bridge driver circuit. Alternatively, in lieu of the driver sub-circuit 38, the electrical power sub-circuit 60 may comprise the master control unit 44. Electrical energy from the power source 46 or the transmitter host device 22 is received by the transmitter driver sub-circuit 38 or master control unit 44. The driver sub-circuit 38 or the master control unit 44 is configured to convert a portion of the electrical power from a direct current electrical power to an alternating current electrical power for wireless transmission. In addition, the driver sub-circuit 38 or master control unit 44 may be configured to adjust the amplitude of the voltage of the received electrical power. The driver sub-circuit 38 or master control unit 44 is also configured to provide electrical power to operate the other components that comprise the transmitter module 12.

In addition to the electrical power sub-circuit 60, the embodiments of the transmitter circuit shown in FIGS. 9 and 10 further illustrate different embodiments of the receiver module sensing sub-circuit 42. As illustrated in the embodiment of FIG. 9, the receiver module sensing sub-circuit 42 comprises an envelope tracker sub-circuit 64 comprising resistors R₅ and R₆ electrically connected in series, diode D₅ electrically connected in series to resistor R₅, and capacitor C₁₁ electrically connected between resistors R₅ and R₆. The envelope tracker circuit 64 is configured to generate an analog voltage signal at node 66 that resides between resistors R₅ and R₆. In an embodiment, the analog voltage is received by an analog to digital converter (not shown) that is electrically connected to the master control unit 44. In an embodiment, when the receiver module 14 is positioned within the magnetic field emanating from the transmitter antenna 20, the receiver antenna 26 within the receiver module 14 begins to resonate. The presence of the receiver antenna 26 within the magnetic field emanating from the transmitter antenna 20 establishes an electrical coupling between the transmitter and receiver antennas 20, 26 creates a shift in electrical impedance that is detected by the transmitter antenna 20. This change in electrical impedance which results when the receiver antenna 26 of the receiver module 14 is positioned within the magnetic field generates a change in electrical voltage at node 66. Thus, this voltage signal alerts the master control unit 44 of the transmitter module 12 which then begins transmission of electrical energy from the transmitter module 12 to the receiver module 14. For example, if a voltage greater than 0 is detected by the transmitter host device 22 or transmitter master control unit 44 from the voltage sense signal, it is determined that the receiver module 14 is present. In an embodiment, if the receiver module 14 is determined to be present, the driver sub-circuit 38 or the transmitter master control unit 44 is activated and electrical power from the transmitter host device 22 or electrical power source 46 is wirelessly transmitted by the transmitter antenna 20 to the receiver module 14.

FIG. 10 illustrates an alternate embodiment of the envelope tracker circuit 64. In addition to resistors R₇, R₈, diode D6, and capacitor C₁₅, the envelope tracker circuit 64 comprises integrated sub-circuit 67 that comprises integrated circuit 68, capacitor C₁₆ and resistors R₉ and R₁₀. In an embodiment, the integrated sub-circuit 67 is configured to convert the analog voltage received at node 69 into a digital signal that is received by the master control unit 44 within the transmitter module circuit 18.

FIGS. 11 and 12, illustrate alternate embodiments of the transmitter module circuit 18. In particular, FIGS. 11 and 12 illustrate alternate embodiments of the electrical power sub-circuit 60. As shown, the electrical power sub-circuit 60 of FIGS. 11 and 12 comprise a field effect transistor Q₁ (FIG. 11) and Q₂ (FIG. 12). In an embodiment, the electrical power sub-circuit 60 of FIGS. 11 and 12 are configured to drive the transmitter antenna 20 to allow for wireless power transfer. In an embodiment, as shown in FIG. 11, the electrical power sub-circuit 60 comprises the field effect transistor (FET) Q₁ that is turned on and off by a control signal from the master control unit 44 or other signal generator, such as a signal generator that resides within the transmitter host device 22 to create the necessary input to control (FET) Q₁ and the wireless electrical power transfer. In an embodiment as illustrated in FIG. 11, the electrical power sub-circuit 60 further comprises resistor R₁₁, capacitors C₁₁, C₁₈ and inductors L₃-L₅.

In an embodiment, as shown in FIG. 12, the field effect transistor (FET) Q₂ is electrically connected to power amplifier 60 comprising resistors R₁₉-R₂₁, inductor L₆, and capacitors C₂₅-C₂₈, and integrated circuits 72 and 74 to modify a direct current (DC) voltage input to an alternating current (AC) amplified voltage signal that drives the transmitter antenna 20 to enable wireless electrical power transfer.

In addition to the electrical power sub-circuit 60, the embodiments of the transmitter module circuit 18 shown in FIGS. 11 and 12 further illustrate various embodiments of the receiver module sensing sub-circuit 42. As shown in FIG. 11, the receiver sensing sub-circuit 42 comprises an operational amplifier 76 comprising capacitors C₂₁-C₂₃, resistors R₁₂-R₁₇ and diode D₈. As shown, the change in electrical impedance is detected at node 78 which resides between the transmitter antenna 20 and the impedance matching circuit 40 comprising capacitors C₁₉ and C₂₀. The electrical impedance is then converted into an electrical current signal at node 80 by diode D₇, resistor Ria, and capacitor C₂₄. The electrical current signal is received by the operational amplifier 76 which is configured to amplify the sense signal received at node 80. In an embodiment, the operational amplifier 76 can also be configured to serve as a comparator in which an envelope detector voltage is compared against a set threshold to determine whether the receiver is present and output a digital signal (i.e., a “LOW” (binary 0) or “HIGH” (binary 1) signal) to the master control unit 44.

The amplified signal is then received by the master control unit 44. In an embodiment, amplifying the sense signal increases the resolution of detection thereby increasing the accuracy of the detecting for the presence of the receiver module 14. In yet another embodiment illustrated in FIG. 12, the receiver sensing sub-circuit 42 comprises an electrical impedance signal conversion sub-circuit 82 and sense control sub-circuit 84. In an embodiment, the electrical impedance signal conversion sub-circuit 82 comprises diode D₉ and resistor R₂₅ which is electrically connected in parallel to capacitor C₃₄. The sense control sub-circuit 84 comprises integrated circuit 86, resistors R₂₂-R₂₇, and capacitors C₃₁-C₃₃. In an embodiment, the electrical impedance at node 88 is converted to an electrical current signal at node 90 by diode D₉, resistor R₂₅, and capacitor C₃₄. The electrical current signal is received by integrated circuit 86 within the sense control sub-circuit 84. In an embodiment, the integrated circuit 86 is configured to convert the electrical current signal into an electrical data signal that sent to the master control unit 44 to notify the presence of the receiver module 14.

FIG. 13 illustrates a block diagram of an embodiment of the receiver module circuit 24 that resides within the receiver module 14 of the present invention. The receiver module circuit 24 is configured to receive electrical power transmitted wirelessly via near field magnetic coupling from the transmitter antenna 20 of the transmitter module 12. As illustrated in FIG. 13, the receiver module circuit 24 comprises the receiver antenna 26, a receiver impedance matching sub-circuit 92, a rectifier 94, and a voltage regulator 96. As shown, the receiver antenna 26 is electrically connected to the receiver impedance matching circuit 92 that is electrically connected to the rectifier 94 and the voltage regulator 96. In an embodiment, the receiver impedance matching circuit 92 is configured to adjust the electrical impedance of the receiver module 14 to match the electrical impedance of the transmitter module 12. The rectifier 94 is configured to modify the received electrical power from an alternating current electrical power to a direct current electrical power. The voltage regulator 96 is configured to adjust the amplitude of the electrical voltage of the wirelessly received electrical power.

FIG. 14 is an electrical schematic diagram of the embodiment of the receiver module circuit 24 shown in FIG. 13. As shown, the receiver antenna 26 comprising inductor L₉ is electrically connected to the impedance matching sub-circuit 92 comprising capacitors C₃₅-C₃₇. The impedance matching sub-circuit 92 is electrically connected to the rectifier 94 that comprises diodes D₁₀-D₁₃ and the voltage regulator 96 comprising a low dropout linear voltage regulator.

FIG. 15 is a block diagram that illustrates an alternate embodiment of the receiver module circuit 24 within the receiver module 14 of the present application. As shown the receiver module circuit 14 comprises the receiver antenna 26, the electrical impedance matching sub-circuit 92, a voltage doubler sub-circuit 98, the voltage regulator 96 and a receiver master control unit 100. In an embodiment, the receiver antenna 26 is electrically connected to the electrical impedance matching circuit 92 which is configured to dynamically adjust and match the electrical impedance of the receiver antenna 26 to a characteristic impedance of the power generator or the load at a driving frequency of the transmitter antenna 20. In the embodiment, the impedance matching circuit 92 is electrically connected to the voltage doubler sub-circuit 98 which is designed to rectify the wirelessly received electrical power from an alternating current electrical power to a direct current electrical power. The voltage doubler circuit 98 is also configured to increase, i.e., double, the voltage of the wirelessly received electrical power. As further shown in the embodiment, the voltage doubler sub-circuit 98 is electrically connected to the voltage regulator 96 which is designed to further adjust the amplitude of the voltage of the wirelessly received electrical power. The voltage regulator 96 is electrically connected to the receiver master control unit 100. In an embodiment, the receiver master control unit 100 is configured to operate the receiver module circuit 24 within the receiver module 14. In an embodiment, the electrical power wirelessly received from the transmitter module 12 and modified by the receiver module circuit 24 is used to power the host device and/or may be used to electrically charge an electrical storage device 102, such as an electrochemical cell or capacitor.

FIG. 16 illustrates an electrical schematic diagram of the receiver module circuit 24 shown in FIG. 15. As shown the receiver antenna 26 which comprises inductor L₁₀, is electrically connected to the electrical impedance matching sub-circuit 92 which comprises at least one capacitor. As illustrated, the electrical impedance matching sub-circuit 92 comprises capacitors C₄₀-C₄₂. As further illustrated in FIG. 16, the electrical impedance matching circuit 92 is electrically connected to the voltage doubler sub-circuit 98 which comprises diodes D₁₄, D₁₅ and capacitor C₄₃. Incorporation of the voltage doubler sub-circuit 98 within the receiver module circuit 24 rectifies the wirelessly received electrical power and increases the amount of electrical power that can be transmitted across the separation distance 16 between the transmitter and receiver modules 12, 14. In addition, the voltage regulator sub-circuit 97 which comprises voltage regulator 96 is electrically connected to resistors R₂₈-R₃₀ and capacitors C₄₄ and Cos is electrically connected to the voltage doubler sub-circuit 98.

In an embodiment, the voltage doubler sub-circuit 98 allows for increased system efficiency due to a decrease in the electrical impedance experienced by the receiver module circuit 24. Experimental results indicate that incorporation of the voltage doubler sub-circuit 98 within the receiver module circuit 24 decreases the electrical impedance of the circuit 24 from about 301Ω to about 31Ω under a no load condition and decreases the electrical impedance from about 154Ω to about 4.9Ω under full load conditions, a decrease in electrical impedance by as much as 97 percent. Since the voltage doubler sub-circuit 98 significantly reduces the electrical impedance of the receiver module circuit 24, incorporation of the voltage doubler sub-circuit 98 within the receiver module circuit 24 thus provides for the transmission of a greater amount of electrical power across a module separation distance 16 at a given frequency. Furthermore, the voltage doubler sub-circuit 98 allows for decreased component sizes and increased system performance. Moreover, the voltage doubler sub-circuit 98 allows for the operation of the system 10, specifically, wireless transfer of electrical energy and data, across a wider module separation distance 16 in comparison to other rectifying topologies (e.g., a full wave rectifier). For example, the receiver module 14 of the present invention configured with the voltage doubler sub-circuit 98 enables wireless transfer of electrical energy and/or data across a module separation distance 16 from about 0.5 mm to about 5 mm. In comparison, a receiver module that is not configured with the voltage doubler sub-circuit 98 allows for the transfer of electrical energy and/or data across a module separation distance 16 from about 0.5 mm to about 2 mm. The voltage doubler sub-circuit 98 thus enables an increase of the module separation distance 16 by about 100 percent or about double the module separation distance 16. Furthermore, at closer separation distances, the electrical impedance of the gate driver or FET power stage is reduced allowing for increased wireless electrical power delivery.

FIG. 17 illustrates a block diagram of an embodiment of the receiver module circuit 24 of the present application. As shown, in addition to the receiver master control unit 100, the receiver antenna 26, the rectifier 94 and voltage regulator 96, the receiver module circuit 24 may be configured with a thermal sense sub-circuit 104. In an embodiment, the thermal sense sub-circuit 104 is configured to monitor the temperature within the receiver module 14. In an embodiment, if the receiver master control unit 100 through the thermal sense sub-circuit 104 detects that the temperature within the receiver module increases from about 20° C. to about 50° C., the receiver master control unit 100 prevents the operation of the receiver module 14. In addition, the receiver module 14 may be configured to receive and transmit data to and from the transmitter module 12. In an embodiment, the receiver module 14 may be configured to modulate and demodulate data from the transmitter module 12 to enable communication therebetween. In an embodiment, the wireless connector system 10 of the present application may be configured for in-band communication, such as in-band amplitude, phase, and/or frequency shift keying communication. In addition, the wireless connector system 10 of the present application may be configured for out of band communication. In band communication is based on the transfer of information/data across a wireless power signal. The wireless power signal is the carrier frequency, and the different methods (amplitude, frequency, and phase) modulate this carrier frequency to deliver the data. Out of band communication utilizes an external signal that is separate from the wireless power signal to deliver data/communication.

FIGS. 18A-18D illustrate embodiments of impedance matching sub-circuits 40, 92 which may be utilized within the receiver module circuit 24 and/or the transmitter module circuit 18. As shown in the embodiment of FIG. 18A, the impedance matching circuit 40, 92 may comprise two capacitors C₄₆ and C₄₈ connected in electrical parallel and a shunt capacitor C₄₇ electrically connected between capacitors C₄₆ and C₄₈. FIG. 18B illustrates an embodiment in which a shunt capacitor C₅₀ is electrically connected in parallel between capacitors C₄₉ and C₅₁. FIG. 18C illustrates an embodiment in which the electrical impedance matching circuit may comprise at least one capacitor C₅₂ electrically connected to the positive side of the receiving or transmitter antenna. FIG. 18D illustrates an embodiment in which two capacitors C₅₃ and C₅₄ are each electrically connected to the positive and negative terminals, respectively of the receiving or transmitter antenna.

In an embodiment, incorporating a shunt capacitor such as those shown in FIG. 18A or 18B enables electrical power to be transmitted across a greater separation distance 16. In an embodiment, the shunt capacitor is used to boost the received voltage into the receiver rectifier 34 in comparison to a series only tuning topology. The shunt capacitor allows the resistance of the antenna to be modified in order to increase the amount of electrical power that can be transferred at a certain distance as well as increase the maximum operating distance of the system. In an embodiment, incorporating the shunt capacitor, as shown in FIG. 18A or 18B, within the electrical impedance matching sub-circuit 92 of the receiver module circuit 24 enables electrical power to be wirelessly transmitted over a 2 mm separation distance. The inventors have discovered that without the use of a shunt capacitor within the electrical impedance matching sub-circuit 92 of the receiver module circuit 24 of the receiver module 14, wireless transmission of the electrical power spans a shorter separation distance. For example, the inventors have discovered that the shunt capacitor enables electrical power to be wirelessly transmitted over a separation distance 16 that is about 50 percent longer in comparison to a receiver module that does not comprise a shunt capacitor for the same amount of electrical power transmitted.

FIGS. 19-22 illustrate embodiments of the wireless connector system 10 comprising the transmitter module 12 and the receiver module 14. As illustrated, the transmitter module 12 comprises a transmitter module housing 106 that encases the transmitter module circuit 18 and transmitter antenna 20 therewithin. The receiver module 14 comprises a receiver module housing 108 that encases the receiver module circuit 24 and receiver antenna 26 therewithin. In an embodiment, either or both the transmitter module housing 106 and the receiver module housing 108 are hermetically sealed. In an embodiment, at least one of the transmitter module housing 106 and the receiver module housing 108 may be composed of a polymeric material, a metal, a ceramic material or combinations thereof. In addition, either or both the transmitter module 12 and receiver module 14 may be immersed within an encapsulate material (not shown). This encapsulate material helps protect the circuitry of the modules 12, 14 and helps ensure a hermetic seal. It is noted that during operation of the wireless connector system 10, the transmitter and receiver modules 12, 14 are positioned such that the module separation distance 16 spans between the modules 12, 14. In an embodiment, the module separation distance 16 may range from about 0.1 mm to about 5 mm. In an embodiment, the module separation distance or gap 16 between the transmitter and receiver modules 12, 14 during operation of the system ranges from about 0.1 mm to about 2 mm. In an embodiment, the wireless connector system 10 of the present invention is configured to wirelessly transmit between about 1 mW to about 200 mW at a frequency greater than 5 MHz. In an embodiment, the wireless connector system 10 is configured to wirelessly transmit between about 1 mW to about 200 mW at a frequency that ranges from about 1 MHz to about 50 MHz between the transmitter and receiver modules 12, 14. In an embodiment, the wireless connector system 10 may operate at any frequency or frequencies, which may include, but is not limited to, 100 kHz, 6.78 MHz, 10 MHz, 13.56 MHz, 27.12 MHz, 433 MHz, 915 MHz, 1.8 GHz, 2.4 GHz, 60 GHz, and 5.7 GHz. In addition, such frequencies may include licensed frequency bands.

In an embodiment both the transmitter and receiver modules 12, 14 are of a compact size. In an embodiment, the transmitter module 12 has a length 110 that extends from a transmitter module proximal end 112 to a transmitter module distal end 114. The transmitter module 12 has a transmitter module width 116 oriented about perpendicular to the length 110. In an embodiment, the receiver module 14 has a receiver module length 120 that extends from a receiver module proximal end 122 to a receiver module distal end 124. The receiver module 14 comprises a receiver module width 126 oriented about perpendicular to the length 120. As illustrated in FIG. 19, in an embodiment, the transmitter module 12 comprises a transmitter module height 118 that extends about perpendicular to transmitter module length 110. In an embodiment, the receiver module 14 comprises a receiver module height 128 that extends about perpendicular to the receiver module length 120.

In an embodiment, either or both the transmitter and receiver modules 12, 14 are configured to be surface mounted. In an embodiment, as shown in FIG. 22, a plurality of brackets 130 mechanically support and electrically connect the modules 12, 14 to a circuit board 132 of the respective host device. In addition, as illustrated in FIG. 21, each of the modules 12, 14 may comprise a plurality of castellations 134 that reside within an exterior surface of the transmitter module housing 106 and/or the receiver module housing 108. These castellations 134 provide a space within which a surface mount (not shown) may be positioned therewithin to mechanically secure the modules 12, 14 to a surface and provide an electrical connection to the host device.

In an embodiment, as shown in FIG. 23, at least one of the transmitter and receiver modules 12, 14 comprises a plurality of metal pads 136 positioned at an edge of an exterior surface of the module housing 106, 108. These metal pads 136 are designed to provide electrical contact of the module 12, 14 to a circuit board 132 or host device 22, 28. Furthermore, the at least one of the transmitter and receiver modules 12, 14 may comprise at least one post 138 that outwardly extends from the exterior surface of the module housing 106, 108. These posts 138 mechanically support and secure the at least one transmitter module and receiver module 12, 14 to a circuit board 132 or a host device 22, 28. In addition, the modules 12, 14 may be electrically connected to circuit boards of their respective host devices through the use of welding, soldering, fasteners, such as pins, spring contacts, and the like.

FIG. 24 illustrates an embodiment of the construction within the housing 106, 108 of the respective modules 12, 14. In an embodiment each of the modules 12, 14 is constructed with a respective transmitter or receiver antenna 20, 26, and a module circuit board residing within the housing 106, 108 of the transmitter or receiver module 12, 14. In an embodiment, a transmitter module circuit board 140 resides within the transmitter module housing 106 and a receiver module circuit board 142 resides within the receiver module housing 108. In an embodiment, the transmitter antenna 20 and receiver antenna 26 resides within the housing 106, 108 at the distal end of their respective modules 12, 14. In an embodiment, the transmitter module circuit board 140 and the receiver module circuit board 142 reside within their respective transmitter module and receiver module housing 106, 108 at the proximal end of their respective modules 12, 14. In an embodiment, the transmitter antenna 20 is electrically connected to the transmitter module circuit board 140 and the receiver antenna 26 is electrically connected to the receiver module circuit board 142 using a flex connector, a board to board connector, a pin and socket connector, a spring contact connector, a pogo pin connector, a through-hole pin solder connector, a soldered wire connection, or a combination thereof.

In an embodiment, at least one of the transmitter and receiver modules 12, 14 may be constructed having a spacer 144 composed of an electrically insulating, non-magnetic material positioned within the housing 106, 108 of the transmitter or receiver module 12, 14. In an embodiment, the at least one spacer 144 is positioned between the transmitter or receiver module circuit board 140, 142 and the transmitting or receiving antenna 20, 26, respectively within the housing 106, 108. In an embodiment, at least one shielding material 146 may be positioned within the housing 106, 108 of either or both the transmitter and receiver modules 12, 14. In an embodiment, the at least one shielding material 146 is positioned between the transmitter or receiver module circuit board 140, 142 and the transmitter or receiver antenna 20, 26, respectively within the housing 106, 108. In an embodiment, the at least one shielding material 146 may be positioned between the transmitter or receiver module circuit board 140, 142 and the at least one spacer 144. In an embodiment, the at least one shielding material 146 may be positioned between the at least one spacer 144 and the transmitter or receiver module antenna 20, 26. As illustrated in the example shown in FIG. 25, the transmitter or receiver antenna 20, 26 is positioned at the distal end of the respective modules 12, 14. A spacer 144 is positioned proximal of the antenna 20, 26, the shielding material 146 is positioned proximal of the spacer 144 and the transmitter or receiver module circuit board 140, 142 is positioned at the proximal end of the module 12, 14. In an embodiment, during operation of the wireless connector system 10 of the present invention, the respective antennas 20, 26 of the transmitter and receiver modules 12, 14 are positioned facing each other across the module separation distance 16. Table I below further illustrates the various sequences of positions within the housing 106, 108. It is noted that Position 1 is the proximal end 112, 122 of the module and Position 4 is the distal end 114, 124 of the module 12, 14, respectively. Position 2 is distal of Position 1 and Position 3 is distal of Position 2.

TABLE I Example Position 1 Position 2 Position 3 Position 4 1 Circuit Board Spacer Spacer Antenna 2 Circuit Board Shield Spacer Antenna 3 Circuit Board Shield Shield Antenna 4 Circuit Board Spacer Shield Antenna

In an embodiment, the circuit board may either be the transmitter module circuit board 140 or the receiver module circuit board 142, the antenna may either be the transmitter antenna 20 or the receiver antenna 26. The spacer 144 may comprise an electrically insulative material such as air, FR4, a polymeric material or a combination thereof. The shielding material 146 may comprise a ferrite material, a metal, or a combination thereof. It is noted that positioning the shielding material 146 closer to the transmitter or receiver antenna 20, 26, such as detailed in Examples 3 and 4, of Table I, provides an increase in electrical inductance that results in an improved mutual inductance between transmitter and receiver modules 12, 14.

As further illustrated in FIG. 25, the electrically conductive bracket 130 electrically connects the circuit boards 140, 142 of the respective transmitter and receiver modules 12, 14 to the host device. As illustrated in the embodiments shown in FIGS. 25 and 26, the host device is a circuit board. FIG. 26 illustrates a further embodiment in which the electrically conductive bracket 130 is positioned between position 1 and position 2. As specifically illustrated in FIG. 26, the bracket 130 is positioned between the transmitter or receiver circuit board 140, 142 and the shielding material 146. Alternatively, the bracket 130 may be positioned between the transmitter or receiver circuit board 140, 142 and the spacer 144.

FIGS. 27-34 illustrate an alternate embodiment of a transmitter module 148 and a receiver module 150 having a hybrid rigid flex printed circuit board construction. In this construction, a module power circuit board, of either a transmitter module power circuit board 152 or a receiver module power circuit board 154 is electrically connected to an antenna assembly of either a transmitter antenna assembly 156 or a receiver antenna assembly 158, respectively (FIG. 27). An electrical bridge or electrical connector 160 extends between and electrically connects the antenna assembly 156, 158 and the module power circuit board 152, 154. This construction can also be used to provide a connection between the transmitter module circuit board 140 and the transmitter antenna 20, and/or the receiver module circuit board 142 and the receiver antenna 26 by encapsulating one or more flexible printed circuit (FPC) layers that comprise the transmitter or receiver antenna 20, 26 inside one or more rigid (FR4) circuit board layers.

FIG. 27 illustrates an embodiment of the components that comprise the transmitter or receiver module 148, 150 having a hybrid rigid flex printed circuit board construction of the present invention. As shown, the module power circuit board of either the transmitter module power circuit board 152 or the receiver module power circuit board 154 is electrically connected to the antenna assembly of either the transmitter antenna assembly 156 or the receiver antenna assembly 158, respectively, by the electrical connector 160. In an embodiment, the electrical bridge or electrical connector 160 is flexible and is capable of bending. In an embodiment, the electrical bridge or electrical connector 160 comprises one or more sheets of copper, a circuit connector ribbon, flexible ribbon, an electrical flex connector, an electrically conductive ribbon, or combinations thereof.

In an embodiment, the transmitter module power circuit board 152 and the receiver module power circuit board 154 comprise a substrate 166 such as FR4 or printed circuit board that is substantially rigid and supports a variety of transmitter module power circuit board electrical components 162 or receiver module power circuit board electrical components 164. In an embodiment, these electrical components 162, 164 may be surface mounted to an exterior surface of the transmitter module power circuit board 152 and the receiver module power circuit board 154, respectively.

In an embodiment, the transmitter and receiver antenna assemblies 156, 158, comprises a substrate 168, such as a rigid printed circuit board or FR4 board that supports the transmitter or receiver antenna 20, 26. As illustrated in FIG. 27, the substrate 168 supports either the transmitter or receiver antenna 20, 26. A shielding material 170, such as a layer of ferrite material, is positioned over the transmitter or receiver antenna 20, 26. In an embodiment, the shielding material 170, such as a sheet of ferrite material may be laminated or adhered to the transmitter or receiver antenna 20, 26 with an adhesive.

In an embodiment, as illustrated in FIG. 28, the antenna assembly 156, 158 is folded over the module power circuit board 152, 154, to form a transmitter module assembly 172 or a receiver module assembly 174, respectively. In an embodiment, as shown in FIG. 29, a second shielding material 176, such as a ferrite material, may be positioned between the antenna assembly 156, 158 and the module power circuit board 152, 154. This construction provides many benefits that include, but are not limited to:

-   -   1. A continuous connection between the antenna assembly 156, 158         and the module power circuit board 162, 164. In an embodiment,         the antenna assembly 156, 158 may be positioned such that         conductive traces of the antenna 20, 26 directly connect to the         module power circuit board 162, 164. This construction reduces         the overall electrical impedance.     -   2. The antenna assembly 156, 158 and module power circuit board         162, 164 comprise a single structure (i.e., the transmitter         module assembly 172 or the receiver module assembly 174), thus         increasing connection reliability and manufacturing yield, and         reducing the number of discrete components, complexity and         assembly cost.     -   3. The structure enables a more simplified manufacturing process         that allows for large scale manufacture.     -   4. Testing is simplified as both, the antenna and the power         board can be tested at the same time.

FIG. 29 illustrates an exploded view of an embodiment of the transmitter module 148 or the receiver module 150 of the present application comprising the receiver or transmitter module assembly 172, 174 respectively. As shown in the embodiment, the transmitter 148 and/or the receiver module 150 comprise a spacer or housing structure 178 that separates the transmitter or receiver antenna assembly 156, 158 from the transmitter or receiver module power circuit board 152, 154, respectively. Alternatively, the housing structure 178 may provide a space therewithin in which the transmitter or receiver module assembly 172, 174 is positioned.

In an embodiment, the housing structure 178 comprises an electrically insulative material and acts as a spacer that separates the transmitter or receiver module assembly 172, 174 from additional shielding material that may be positioned on an exterior surface of the housing structure 178. As shown in the embodiment illustrated in FIG. 29, a third and fourth shielding material 180, 182, such as a ferrite material, may be positioned on the exterior surface of the housing structure 178. In an embodiment a layer of a rigid circuit board material 184 may be positioned in contact with the third and fourth shielding materials 180, 182 to provide added structural support. In an embodiment, the transmitter module 148 or the receiver module 150 may comprise a retention fastener 186 and/or a locating post 188 that outwardly extend from the housing sidewall. In an embodiment, the retention fastener 186 and/or the locating post 188 are used to precisely position the module 148, 150 on the transmitter module or receiver module host device 22, 28, such as a printed circuit board. In an embodiment, the retention fastener 186 and/or the locating post 188 retain the transmitter module 12 and/or the receiver module 14 to the respective host device 22, 28. Furthermore, the retention fastener 186 and/or the locating post 188 may be electrically connected to the respective host device 22, 28.

FIG. 30 illustrates an embodiment of an assembled transmitter or receiver module 148, 150 comprising two retention fasteners 186 and the locating post 188 that outwardly extend from the module housing structure 178. As shown, the housing structure 178 is positioned between the transmitter or receiver module power circuit board 152, 154 and the transmitter or receiver antenna assembly 156, 158. In this way, the retention fasteners 186 improve component retention that provides for balanced soldering and helps prevent potential component delamination during a solder reflow process. Furthermore, the retention fasteners 186 and the locating post 188 provide alignment guides for installation of the modules 148, 150.

FIG. 30A illustrates a cross-sectional view of the embodiment of the assembled module 12, 14 shown in FIG. 30. As shown, the module circuit board 140, 142 is positioned opposed from the antenna assembly 156, 158. The module spacer or housing structure 178 is positioned therebetween. In an embodiment, the spacer 178 may be of a solid structure having various cutouts for the positioning of the electrical components 162, 164. Alternatively, the spacer 178 may be constructed having a void space therewithin for the positioning of the electrical components 162, 164. In an embodiment, the spacer 178 may be constructed having a void space therewithin for the positioning of the module circuit board 140, 142 and the antenna assembly 156, 158. As illustrated, an adhesive layer 187 may be to adhere the module circuit board 140, 142 and the antenna assembly 156, 158 to the spacer 178.

FIGS. 31-34 illustrate various embodiments of the transmitter and receiver modules 148, 150 shown in FIGS. 27-30, mounted to a host device 22, 28 such as a circuit board. As shown, the modules 148, 150 may comprise a plurality of pads 190 that are electrically connected to the host device circuit board. Furthermore, as illustrated in FIG. 34, the modules 148, 150 may comprise alignment legs 192 (FIG. 34) that outwardly extend from the housing structure 178. In an embodiment, the alignment legs 192 provide an additional alignment aid and provide additional mechanical stability when the modules 148, 150 are mounted into an opening in the board 194 of the host device 22, 28. In an embodiment shown in FIG. 34, the transmitter and receiver modules 148, 150 may be positioned within an opening 194 that extends through the thickness of the host device circuit board 22, 28.

FIG. 35 illustrates a top view of an embodiment of an antenna 20, 26 that may be used with either of the transmitter module 12, 148 or the receiver module 14, 150. In an embodiment, the antenna 20, 26 is of a flat spiral coil configuration. In the embodiment shown, the antenna comprises four layers of alternating of an electrical conductor and electrically insulating layers integrated into a printed circuit board (PCB) or flexible circuit board (FPC). As shown, the antenna 20, 26 comprises two antenna segments that are electrically connected in series. As shown, the antenna 20, 26 is constructed having five turns of a copper trace 196 deposited on the surface of an insulative substrate 198 with a gap 200 of 15 to 200 microns between each trace 196. Each segment comprises an electrical conductor (e.g., trace 196) positioned on an insulative substrate 198 in an electrical parallel configuration. Non-limiting examples can be found in U.S. Pat. App. Nos. 2017/0040690, 2017/0040692, 2017/0040107, 2017/0040105, 2017/0040696, and 2017/0040688 all to Peralta et al., 2017/0040691, 2017/0040694 to Singh et al., 2017/0040693 to Luzinski and 2017/0040695 to Rajagopalan et al. all of which are assigned to the assignee of the present application and incorporated fully herein.

In addition, the antenna 20, 26 may be constructed having a multi-layer-multi-turn (MLMT) construction in which at least one insulator is positioned between a plurality of conductors. Non-limiting examples of antennas having an MLMT construction that may be incorporated within the transmitter module 12, 148 and/or the receiver module 14, 150 may be found in U.S. Pat. Nos. 8,610,530, 8,653,927, 8,680,960, 8,692,641, 8,692,642, 8,698,590, 8,698,591, 8,707,546, 8,710,948, 8,803,649, 8,823,481, 8,823,482, 8,855,786, 8,898,885, 9,208,942, 9,232,893, 9,300,046, all to Singh et al., assigned to the assignee of the present application are incorporated fully herein. It is also noted that other antennas such as, but not limited to, an antenna configured to send and receive signals in the UHF radio wave frequency such IEEE standard 802.15.1 may be incorporated within the wireless connector system 10 of the present invention.

The wireless connector system 10 is designed to operate in an efficient, stable and reliable manner to satisfy a variety of operating and environmental conditions. The system is designed to operate in a wide range of thermal and mechanical stress environments so that data and/or electrical energy is transmitted efficiently and with minimal loss. In addition, the wireless connector system 10 is designed with a small form factor using a fabrication technology that allows for scalability, and at a cost that is amenable to developers and adopters. In addition, the wireless connector system 10 is designed to operate over a wide range of frequencies to meet the requirements of a wide range of applications.

In an embodiment the system may transmit electrical power on the order of about 100 μW to about 10 W. In another embodiment, electrical power around about 100 W may also be transmitted. Specifically considering near field magnetic coupling (NFMC) as the mechanism of wireless power transfer between the transmitter module 12, 148 and the receiver module 14, 150, it is well known that smaller sizes are generally more easily achievable if a higher operating frequency is selected. This is due to the inverse relationship of the required mutual inductance and the frequency of operation, as indicated by the following equation:

$M = \frac{V_{induced}}{j*\omega*I_{Tx}}$

Where:

-   -   V_(induced) is induced voltage on the receiver coil     -   I_(tx) is the AC current flowing through the transmitter coil     -   ω is the operating frequency multiplied by 2π

Since the required mutual inductance increases in order to enable the wireless transfer of electrical energy having increased, it is necessary to increase the inductance or coupling of the transmitter or receiver while minimizing AC losses. Mutual inductance can be calculated by the following relationship:

M=k*√{square root over (L _(Tx) *L _(Rx))}

-   -   M is the mutual inductance of the system     -   k is the coupling of the system     -   L_(Tx) is the inductance of the transmitter coil     -   L_(Rx) is the inductance of the receiver coil

As the form factor of the antenna coil is reduced, attaining the required inductance on either the receiver or transmitter is accompanied by an increase in antenna coil resistance as the high number of turns required leads to a reduction in trace width. This increase in resistance typically reduces the quality factor of the coil and overall coil to coil efficiency of the system where the Quality factor is defined as:

$Q = \frac{\omega*L}{R}$

Where:

-   -   Q is the quality factor of the coil     -   L is the inductance of the coil     -   ω is the operating frequency of the coil in radians/s.     -   Alternatively, the frequency of operation in Hz is co divided by         2H     -   R is the equivalent series resistance at the operating frequency         And coil to coil efficiency is defined as:

${Eff} = \frac{k^{2}*Q_{Rx}*Q_{Tx}}{\left( {1 + \sqrt{\left( {1 + {k^{2}*Q_{rx}*Q_{tx}}} \right)}} \right)^{2}}$

Where:

-   -   Eff is the antenna to antenna efficiency of the system     -   k is the coupling of the system     -   Q_(rx) is the quality factor of the receiver     -   Q_(tx) is the quality factor of the transmitter

In an embodiment, the ferrite shield may be incorporated within the antenna structure to improve antenna performance. Selection of the ferrite shield material is dependent on the operating frequency as the complex magnetic permeability (μ=μ′-j*μ″) is frequency dependent. The material may be a sintered flexible ferrite sheet or a rigid shield and be composed of varying material compositions. Examples of materials may include, but are not limited to, zinc comprising ferrite materials such as manganese-zinc, nickel-zinc, copper-zinc, magnesium-zinc, and combinations thereof.

In addition, depending on the operating frequency and power requirements of the wireless connector system 10, a hybrid Litz wire and PCB coil antenna construction combination may be necessary to efficiently transfer power. In an embodiment, a hybrid Litz wire and PCB coil combination may comprise the transmitter antenna 20 or the receiver antenna 26 of a wrapped Litz wire construction and the other of the transmitter antenna 20 or the receiver antenna 26 may be constructed having a coil disposed on a surface of a circuit board such as the antenna shown in FIG. 35. Lower operating frequencies on the order of 100 kHz to several MHz range may require a certain mutual inductance between the transmitter and receiver antenna 20, 26. This is attainable by using a transmitter antenna 20 of a Litz wire construction having a novel ferrite core in combination with a receiver antenna 26 comprising a coil disposed on a surface of a circuit board, such as the antenna shown in FIG. 35.

In order to increase mutual inductance, the coupling and/or inductance of the transmitter module 12, 148 or the receiver module 14, 150 must be increased. However, due to the small form factor constraints, coupling is limited by the physical size of the connector modules. It is noted that using transmitter and receiver antennas 20, 26 of a construction comprising a coil disposed on the surface of a circuit board, such as the antenna shown in FIG. 35, may increase inductance and increase the resistance of the antenna coils thereby decreasing the quality factor Q and antenna to antenna efficiency.

In an embodiment, the wireless connector system 10 comprising a transmitter module 12, 148 having a transmitter antenna 20 of a Litz-wire construction and a shielding material and a receiver module 14, 150 having a receiver antenna 26 comprising a coil disposed on a surface of a circuit board (FIG. 35) may be used to increase the coupling and mutual inductance of a small form factor of the wireless connector system 10. To achieve a higher antenna to antenna efficiency, this configuration may be used to achieve the necessary power transfer while maintaining high Q factor at lower frequencies. These improvements may also increase the overall performance of the wireless connector system 10 having a relatively small form factor.

The choice of coil design and construction is determined by a combination of the following electrical and magnetic parameters:

-   -   Inductance     -   ESR (equivalent series resistance) at operating frequency     -   Coupling (k)     -   Mutual inductance (M)

For lower operating frequencies, i.e., from about 100 kHz to about 10 MHz, and for achieving increased power transmission on the order of about 0.1 mm to about 100 mm, this particular antenna topology is beneficial. For example, per the mutual inductance equations, if the power to be delivered to a load is constant, while the operating frequency decreases, the mutual inductance between the transmitter and receiver antenna coils increases at a constant transmit current. Table II illustrates the improvement in mutual inductance. Table III illustrates the improvement in coupling and Table IV illustrates the improvement in antenna to antenna efficiency.

TABLE II Transmitter Transmitter Receiver Antenna Antenna Antenna Construction Shield Construction M (μH) Coil on FR4 Sheet Coil on FR4 0.35 PCB PCB Litz Wire T-Core Coil on FR4 1.35 PCB

TABLE III Transmitter Transmitter Receiver Antenna Antenna Antenna Construction Shield Construction Coupling Coil on FR4 Sheet Coil on FR4 0.26 PCB PCB Litz Wire T-Core Coil on FR4 0.29 PCB

TABLE IV Transmitter Transmitter Receiver Antenna to Antenna Antenna Antenna Antenna Construction Shield Construction efficiency Coil on FR4 Sheet Coil on FR4 57.9% PCB PCB Litz Wire T-Core Coil on FR4 80.8% PCB

In addition, if the system 10 is operated at a higher frequency, i.e., on the order of about 1 MHz or greater, the required mutual inductance will be reduced, thereby allowing for smaller transmitter and receiver antennas 20, 26 and modules 12, 14, 148, 150. As defined herein shielding material is a material that captures a magnetic field. An example of which is a ferrite material. In the embodiments detailed in Tables II-IV, a sheet of ferrite material is positioned directly adjacent to the transmitter antenna 20, for example, behind the transmitter antenna 20. As defined herein a “T-Core” shielding material is a magnetic field shield assembly comprising a sheet of shielding material, such as a ferrite material, placed directly behind the transmitter or receiver antenna 20, 26 and an additional second shielding material, such as a ferrite material, placed within the inside area of a coil in the plane of the transmitter or receiver antenna 20, 26. Furthermore, the transmitter module 12, 148 or the receiver module 14, 150 may be constructed having the respective transmitter or receiver antennas 20, 26 comprising a “C-core” shielding material in which the shielding material, such as a ferrite material, configured similarly to the letter “C”, is positioned adjacent to the antenna 20, 26. In addition, the transmitter module 12, 148 or the receiver module 14,150 may be constructed having the respective transmitter or receiver antennas 20, 26 comprising a “E-core” shielding material in which the shielding material, such as a ferrite material, configured similarly to the letter “E”, is positioned adjacent to the antenna 20, 26.

In an embodiment, the wireless connector system 10 rated for a maximum 200 mW received DC power, can be configured having each transmitter module 12, 148 and receiver module 14, 150 comprise a form factor of about 11 mm×4 mm, and operate at a frequency that ranges from about 2 MHz to 30 MHz. However, this presents a key challenge in the antenna design. It is not typically cost effective, nor is it particularly reliable, to implement a wire wound Litz antenna that can fit in a footprint as small as 11 mm×4 mm. Furthermore, as the operating frequency is increased to about 6 MHz and greater, wire wound Litz antenna coils may not be suitable in terms of performance.

Utilizing relatively small sized printed circuit board or flexible printed circuit board (PCB/FPC) based coil-antennas allow for appropriate stackups, appropriate trace widths, gap widths and copper (or other conductive material) depths that are more suitable for higher frequencies. Further, printed circuit board and flex printed circuit board based coil-antennas are highly integrated into the PCB fabrication process, thereby allowing for integration with the rest of the circuitry. This also allows for the integration of MLMT antenna designs to reduce ESR and improve the Q of the antennas.

Furthermore, utilizing coils in a layered approach allows for other fabrication processes, for example, printing, printing on fabrics, semiconductor fabrication processes, such as a low temperature co-fired ceramic (LTCC) process, a high temperature co-fired ceramic (HTCC) process, and the like.

Small form factor PCB coil designs are suitable at higher operating frequencies due to a lower required inductance while maintaining a low coil ESR to minimize the power dissipated in the transmit and receive coils. Printed circuit board (PCB) coil antennas offer additional benefits from a manufacturing, cost and assembly standpoint compared to wire-wound antenna coil solutions. For applications with a strict requirement for overall assembly thickness, printed circuit board (PCB) coil antennas are preferred due to the reduced thickness possible even with multilayer construction.

The ferrite shield material selected for the coil combination also depends on the operating frequency as the complex magnetic permeability (μ=μ′-j*μ″) is frequency dependent. The material may be a sintered flexible ferrite sheet or a rigid shield and be composed of varying material compositions.

It is noted that the construction of the antenna 20, 26 is non-limiting. The antenna that is incorporated within a module may comprise magnetic wires or have a stamped metal construction. Furthermore, the antenna 20, 26 may utilize thick film, thin film or other printing fabrication technologies in its construction.

In an embodiment, incorporation of a transmitter or receiver antenna 20, 26 having a multi-layer-multi-turn (MLMT) construction significantly reduces the equivalent series resistance (ESR) of the respective transmitter module 12, 148 and receiver modules 14, 150 and the wireless connector system 10 of the present invention. The inventors have discovered that incorporation of at least one transmitter and receiver antenna 20, 26 having a multi-layer-multi-turn (MLMT) construction reduces equivalent series resistance (ESR) of the transmitter or receiver module 12, 14 by about 50 percent.

Furthermore, reducing ESR improves the overall system efficiency and reduces heating in the antenna 20, 26 and the system 10 by reducing the (I′×R) losses in the coil. Table V shown below details the measured ESR for two multi-layer-multi-turn (MLMT) antenna designs in comparison to an antenna constructed comprising Litz wire wrapped around an inductor. As shown in Table V below, the antenna constructed with an MLMT design exhibited a lower inductance, (0.60 pH) and a lower equivalent series resistance (ESR) (0.50Ω) in comparison to the antenna having a traditional wound Litz wire construction. Thus, the transmitter or receiver antenna 20, 26 having a multi-layer-multi-turn (MLMT) construction contributes to the increased electrical performance of increased electrical power transmission and increased module separation distance 16 of the wireless connector system 10 of the present invention.

TABLE V Frequency Inductance Antenna Design (MHz) (μH) ESR (Ω) Litz Wire 2 3.80 0.97 MLMT 2 0.60 0.50 MLMT 10 0.65 1.05

Exemplary ways of connecting the module to a host device include, but are not limited to, directly soldering or placing the at least one transmitter module 12, 148 and receiver module 14, 150 on a circuit board or a host device 22, 28. Alternatively, the at least one transmitter module 12, 148 and receiver module 14, 150 could be connected to a circuit board or a host device 22, 28 using a wire/cable. Once connected to a host device 22, 28, the full structure or at least a portion of the structure of the at least one transmitter module 12, 148 and receiver module 14, 150 may be encapsulated within an insulative coating.

In an embodiment, the operating procedure for the transmitter module 12, 148 that comprises a single antenna element may have the following operating process. In this embodiment, the wireless connector system 10 is a unidirectional power transfer system at a frequency, for example at 2.4 GHz. In an embodiment, the receiver module 14, 150 is brought in the vicinity of the transmitter module 12, 148.

In an embodiment, the receiver sensing sub-circuit 42 within the transmitter module 12, 148 detects the presence of the receiver module 14, 150. The master control unit (MCU) 44 within the transmitter module 12, 148 activates the system 10, and an identification stage is initiated. The identification stage could be important to distinguish between a spurious sense signal versus a sense signal detecting a true receiver module 14, 150. The identification could also be important to determine the specific type of the receiver module 14, 150 that would indicate to the transmitter module 12, 148 and the host device 22 what amount of power and type of data to transmit.

In an embodiment, once a positive identification of the receiver module 14, 150 is made, the transmitter module 12, 148 starts transmitting power. In an embodiment, the transmission of electrical power could cease under several conditions, including but not limited to:

-   -   (1) removal of the receiver module     -   (2) a thermal event wherein there is a temperature rise within         the system that rises above a predetermined accepted limit (this         thermal event could be at the transmitter module 12, 148 or the         receiver module 14, 150)     -   (3) if the receiver module 14, 150 powers a battery, then the         battery is fully charged     -   (4) the power supply to the transmitter module 12, 148 is         removed     -   (5) if the power supply to the transmitter module 12, 148 is a         battery, then the electrical power from the battery has dropped         below a pre-determined threshold

It is noted that the above exemplary process is for a case when the transmitter module 12, 148 is configured as a single-purpose (only transmits) and the receiver module 14, 150 is configured as a single purpose (only receives), and there exists a single antenna element for each transmitter module 12, 148 and receiver module 14, 150. In other words, this is a unidirectional wireless power system.

In another embodiment, the wireless connector system 10 of the present application could include a module that can operate both as a transmitter and as a receiver, i.e. a transceiver. In a further embodiment, the wireless connector system 10 of the present application may comprise a power and data transfer system in addition to a single antenna where the data is modulated into the power frequency.

In another embodiment, the wireless connector system 10 of the present invention may comprise multiple antennas within each transmitter module 12, 148 and receiver modules 14, 150. If a multiple antenna system is employed, then the first antenna could be reserved for identification, diagnostics and any uni- or bi-directional data transfer, while the second antenna can be dedicated to power transfer.

In an embodiment, the reliability and repeatability of the receiver module presence sensing capability could be improved by using a calibration method, as described in the following steps.

-   -   1. When the transmitter module 12, 148 is in idle mode, and no         object (such as the antenna coil of the receiver module) is         present, the sense line within the transmitter module circuit 18         may be amplified or buffered and then connected to an Analog to         Digital Converter (ADC). The ADC monitors (or samples) the sense         line at predetermined time intervals converts the sense voltage         in idle mode (Vidle) to a digital format whose value is stored         in memory by the transmitter master control unit (MCU) 44.     -   2. The ADC continues to sample the sense line while in idle mode         by measuring the voltage (Vidle) and calculates the difference         between consecutive values of Vidle designated as Videlta. A         predetermined voltage threshold designated as Vthreshold is used         to compare to Videlta. In this case, Videlta is less than         Vthreshold since the changes in Vidle will be small while the         device remains in idle mode (Scenario 1)     -   3. When an object is present (such as a receiver antenna coil)         the sense line changes to a different voltage level (Vactive)         due to the mutual inductance (M) between the transmitter module         12, 148 and the receiver antenna coil. The ADC converts Vactive         to a digital format whose value is stored in memory by a         microcontroller or master control unit (MCU) of the transmitter         module 12, 148.     -   4. The processor calculates the difference between the stored         value of Vidle and Vactive which is designated as Vadelta and         stores this value in a memory. The same predetermined threshold         Vthreshold is used and compared to Vadelta along with subsequent         samples of Vactive. In this case, since the sense line voltage         has changed and Vadelta will be greater than Vthreshold which         indicates the presence of a receiver antenna coil. The processor         can now switch the device to active mode (Scenario 2)     -   5. The ADC continues to sample the sense line while in active         mode by measuring the voltage (Vactive) and calculates the         difference between consecutive values of Vactive designated as         Vadelta. The same predetermined voltage threshold designated as         Vthreshold is used to compare to Vadelta. In this case, Vadelta         is less than Vthreshold since the changes in Vactive will be         small while the device remains in active mode (Scenario 3)     -   6. When an object is removed (such as a receiver antenna coil)         the sense line returns to the idle mode voltage level (Vidle)         due to the Mutual Inductance (M) between the transmitter and         receiver antenna coils. The ADC converts Vidle to a digital         format whose value is stored in memory by a microcontroller or         processor.     -   7. The processor within the transmitter module 12, 148         calculates the difference between the stored value of Vactive         and Vidle which is designated as Videlta and stores this value         in memory. The same predetermined threshold Vthreshold is used         and compared to Videlta along with subsequent samples of Vidle.         In this case, since the sense line voltage has changed Videlta         will be greater than Vthreshold which indicates the removal of         the receiver antenna coil. The processor can now switch the         device back to idle mode (Scenario 4)     -   8. It should be noted that this methodology is         “self-calibrating” since any variation due to inherent         manufacturing process tolerances are removed. The methodology         also eliminates the need for a comparator and allows the use of         lower cost components since greater module variability can be         tolerated.

As used herein, the phrase “at least one of” preceding a series of items, with the term “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase “at least one of” does not require selection of at least one of each item listed; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C.

The predicate words “configured to”, “operable to”, and “programmed to” do not imply any particular tangible or intangible modification of a subject, but, rather, are intended to be used interchangeably. In one or more embodiments, a processor configured to monitor and control an operation or a component may also mean the processor being programmed to monitor and control the operation or the processor being operable to monitor and control the operation. Likewise, a processor configured to execute code can be construed as a processor programmed to execute code or operable to execute code.

A phrase such as “an aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. An aspect may provide one or more examples of the disclosure. A phrase such as an “aspect” may refer to one or more aspects and vice versa. A phrase such as an “embodiment” does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. A disclosure relating to an embodiment may apply to all embodiments, or one or more embodiments. An embodiment may provide one or more examples of the disclosure. A phrase such an “embodiment” may refer to one or more embodiments and vice versa. A phrase such as a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A configuration may provide one or more examples of the disclosure. A phrase such as a “configuration” may refer to one or more configurations and vice versa.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” or as an “example” is not necessarily to be construed as preferred or advantageous over other embodiments. Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim.

All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”

Reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the subject disclosure.

While this specification contains many specifics, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of particular implementations of the subject matter. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub combination or variation of a sub combination. 

What is claimed is:
 1. A transmitter module configured for wireless power transfer within a given frequency range, the transmitter module comprising: a transmitter antenna that is configured to engage in wireless transmission of electrical energy via near-field magnetic coupling; and control circuitry that is configured to (a) sense whether any receiver module configured for wireless power transfer within the given frequency range is in a near field of the transmitter module and (b) based on the sensing, control an activation state of the transmitter antenna's wireless transmission of electrical energy, wherein control circuitry comprises: a first circuit that comprises an envelope detector and is configured to output a voltage level that is indicative of an impedance detected by the transmitter antenna, wherein the impedance detected by the transmitter antenna is dependent on whether any receiver module configured for wireless power transfer within the given frequency range is in the near field of the transmitter module; and a second circuit configured to (i) monitor the voltage level output by the first circuit and (ii) based on the monitored voltage level, determine whether the activation state of the transmitter antenna's wireless transmission of electrical energy is to be changed.
 2. The transmitter module of claim 1, wherein the envelope detector comprises first and second resistors that are electrically connected in series to one another, and wherein the voltage level output by the first circuit comprises a voltage level at a node residing between the first and second resistors.
 3. The transmitter module of claim 2, wherein the envelope detector further comprises a diode that is electrically connected between the first resistor and the transmitter antenna.
 4. The transmitter module of claim 2, wherein the envelope detector further comprises a capacitor that is connected to the node residing between the first and second resistors.
 5. The transmitter module of claim 1, wherein the second circuit comprises an amplifier that is configured to amplify the voltage level output by the first circuit.
 6. The transmitter module of claim 1, wherein the second circuit comprises an analog to digital converter.
 7. The transmitter module of claim 1, wherein the second circuit comprises an operational amplifier.
 8. The transmitter module of claim 1, wherein the second circuit is configured to monitor the voltage level output by the first circuit by periodically sampling the voltage level.
 9. The transmitter module of claim 1, wherein the second circuit is configured to determine whether the activation state of the transmitter antenna's wireless transmission of electrical energy is to be changed by determining whether the monitored voltage level has changed by a threshold amount.
 10. The transmitter module of claim 9, wherein the second circuit is configured to either (i) determine that the activation state of the transmitter antenna's wireless transmission of electrical energy need not be changed if the monitored voltage level is not determined to have changed by the threshold amount, (ii) determine that the activation state of transmitter antenna's wireless transmission of electrical energy is to be changed from deactivated to activated if the monitored voltage level is determined to have increased by the threshold amount, or (iii) determine that the activation state of transmitter antenna's wireless transmission of electrical energy is to be changed from activated to deactivated if the monitored voltage level is determined to have decreased by the threshold amount.
 11. The transmitter module of claim 1, wherein the second circuit is further configured to output a control signal indicting whether the activation state of the transmitter antenna's wireless transmission of electrical energy is to be changed.
 12. The transmitter module of claim 11, wherein the control circuitry further comprises: a third circuit configured to (i) receive the control signal output by the second circuit and (ii) control the activation state of the transmitter antenna in accordance with the received control signal.
 13. The transmitter module of claim 12, wherein the third circuit is configured to initiate an identification stage for a receiver module if the received control signal indicates that the activation state of the transmitter antenna's wireless transmission of electrical energy is to be changed from deactivated to activated.
 14. The transmitter module of claim 12, wherein the third circuit comprises a microcontroller.
 15. The transmitter module of claim 1, further comprising: a power stage inverter; and an impedance matching circuit, wherein the power stage inverter is connected to the transmitter antenna via the impedance matching circuit.
 16. The transmitter module of claim 15, wherein the first circuit is connected to a node residing between the transmitter antenna and the impedance matching circuit.
 17. The transmitter module of claim 1, wherein the control circuitry is further configured to (a) sense whether any undesired object is in the near field of the transmitter module and (b) based on the sensing, control the activation state of the transmitter antenna's wireless transmission of electrical energy.
 18. The transmitter module of claim 1, wherein the control circuitry is further configured to (a) monitor a temperature level within the transmitter module and (b) based on the monitored temperature level, control the activation state of the transmitter antenna's wireless transmission of electrical energy. 